The present invention relates to a solenoid valve for fluid media, in particular heated water. The valve has a valve housing in which a valve chamber is disposed. The valve chamber is connected directly via an inlet conduit with a valve inlet, and is connected via a valve seat and an outlet conduit with a valve outlet. The valve has a solenoid system that is disposed on the upper side of the valve housing and has a solenoid coil. An armature extending within the solenoid coil has one end connected to a valve disk via a valve stem that extends into the valve chamber, which is sealed from the inner space of the solenoid system by a valve diaphragm. The inner or inside edge of the diaphragm is fixed on the valve stem or on the valve disk, and the outer or outside edge is fixed on the valve housing. At least a portion of the length of the upper inside wall of the inlet conduit adjoining the valve chamber is slanted downward as it extends toward the valve chamber. An example of such a valve is disclosed in DE 101 62 794 A1.
In known valves the diaphragm, by means of which the valve chamber is sealed from the inner space of the solenoid system, is constructed in the form of a conventional folded bellow into which is also integrated the valve disk. Such a bellow construction has on its upper end a circumferential fold. This fold can collect air or vapor bubbles. This collection of bubbles can become so great that the bubbles extend back into the inlet conduit. It has been found that in the region of such bubbles a particularly intense calcification of the valve takes place and the accuracy of the flow rate becomes impaired.
In a version of the prior-art valve, the inlet conduit possesses along at least a portion of its length an upper inside wall that slopes downward as it extends toward the valve chamber. Through this construction it is intended that that bubbles forming in the liquid medium are directed out and away against the direction of flow. It has been found, however, that this construction alone is not sufficient to also carry off the bubbles that accumulate in the bellow folds.